This invention relates to a concrete post and panel noise barrier, and in particular, to a system for reinforcing a grooved post used in this type of barrier.
Concrete posts have long been used in applications such as concrete noise barriers. Such posts are commonly reinforced with metal bars or mesh in order that the posts can bear high loads. Differing sectional shapes of such posts require that the reinforcing assemblies have specialized design to adequately handle lateral as well as axial stress. Typically, such concrete posts or columns are vertically reinforced by a system of longitudinal bars, and laterally reinforced by ties or by continuous, closely spaced spirals. Such lateral reinforcements restrain the longitudinal bars from buckling when the concrete is placed under axial load in actual operation. They also directly restrain the bulging tendency of the concrete itself, enabling the concrete to resist high axial loads when placed in compression. Without such ties, the columns are apt to undergo longitudinal fractures and ultimate structural failure.
While posts of square or rectangular sections can be strongly reinforced by a simple system of ties rather inexpensively, those posts used for walls such as tall highway noise barriers must accommodate panel members between the posts. Such noise barriers have become common along heavily trafficked highways and are described in greater detail in U.S. Pat. Nos. 4,605,090 and 4,862,992. Safety considerations require that post and panel barriers be able to withstand heavy wind loading as well as other lateral axial stresses. Modern designs of such noise barriers utilize spaced apart posts having side grooves for slidably receiving large flat concrete panels. These posts require more complex reinforcing assemblies of ties and stirrups. A reinforcing assembly for a post suitable for use in this type of barrier system is disclosed in Pennsylvania State Contract Guidelines dated Jan. 23, 1989 and issued by the Department of Transportation, Harrisburg, Pa. This post assembly requires the use of heavy reinforcing stirrups which are expensive to construct and difficult to install. Additionally, the component parts of the stirrup assembly are not integrated into a coherent unit. As a result, the concrete will thereby crack under load and ultimately fail.